Humerus

Question 1

Proximal humeral fracture mechanism

Answer 1

• young: high energy trauma (MVC)

* elderly: FOOSH from standing height in osteoporotic individuals

Question 2

Proximal humeral fracture clinical features

Answer 2

• proximal humeral tenderness, deformity with severe fracture, swelling, painful ROM, bruising extends down arm and chest

Question 3

Proximal humeral fracture investigations

Answer 3

• test axillary nerve function (deltoid contraction and skin over deltoid)
• X-rays: AP, trans-scapular, axillary are essential
• CT scan: to evaluate for articular involvement and fracture displacement

Question 4

Proximal humeral fracture classification

Answer 4

• Neer classification is based on 4 fracture locations or ‘parts’
1) Greater tuberosity
2) Lesser Tuberosity
3) Humeral Head
4) Shaft
One-part fracture - any of the 4 parts with none displaced
Two-part fracture - any of the 4 parts with 1 displaced
Three-part fracture - displaced fracture of surgical neck + displaced greater tuberosity or lesser tuberosity
Four-part fracture - displaced fracture of surgical neck + both tuberosities

• displaced: displacement >1 cm and/or angulation >45°
• the Neer system regards the number of displaced fractures, not the fracture line, in determining classification
• ± dislocated/subluxed: humeral head dislocated/subluxed from glenoid

Question 5

Proximal humeral fracture treatment

Answer 5

• treat osteoporosis if needed

• non-operative
■ nondisplaced: broad arm sling immobilization, begin ROM within 14 d to prevent stiffness
■ minimally displaced (85% of patients) - closed reduction with sling immobilization x 2 wk, gentle ROM

• operative
■ ORIF (anatomic neck fractures, displaced, associated dislocated glenohumeral joint)
■ hemiarthroplasty or reverse TSA may be necessary, especially in elderly

Question 6

Proximal humeral fracture specific complications

Answer 6

• AVN, nerve palsy (45%; typically axillary nerve), malunion, post-traumatic arthritis

Anatomic neck fractures disrupt blood supply to the humeral head and AVN of the humeral head may ensue

Question 7

Humeral shaft fracture mechanism

Answer 7

high energy: direct blows/MVC (especially young)

low energy: FOOSH, twisting injuries, metastases (in elderly)

Question 8

Humeral shaft fracture clinical features

Answer 8

• pain, swelling, weakness ± shortening, motion/crepitus at fracture site
• must test radial nerve function before and after treatment: look for drop wrist, sensory impairment dorsum of hand

Question 9

Humeral shaft fracture investigations

Answer 9

X-ray: AP and lateral radiographs of the humerus, including the shoulder and elbow joints

Question 10

Humeral shaft fracture treatment

Answer 10

• in general, humeral shaft fractures are treated non-operatively

• non-operative
■ ± reduction; can accept deformity due to compensatory ROM of shoulder
■ hanging cast (weight of arm in cast provides traction across fracture site) with collar and cuff sling immobilization until swelling subsides, then Sarmiento functional brace, followed by ROM

• operative
■ indications: NO CAST, pathological fracture, “floating elbow” (simultaneous unstable humeral and forearm fractures)
■ ORIF: plating (most common), IM rod insertion, external fixation

Question 11

Humeral shaft fracture specific complications

Answer 11

• radial nerve palsy: expect spontaneous recovery in 3-4 mo, otherwise send for EMG
• non-union: most frequently seen in middle 1/3
• decreased ROM
• compartment syndrome

brachial artery injury

Question 12

Acceptable humeral shaft deformities for non-op tx

Answer 12

<20o anterior angulation

<30o varus angulation

<3 cm of shortening

Question 13

Distal humeral fracture mechanism

Answer 13

• young: high energy trauma (MVC)

* elderly: FOOSH

Question 14

Distal humeral fracture clinical features

Answer 14

• elbow pain and swelling

* assess brachial artery

Question 15

Distal humeral fracture investigations

Answer 15

• X-ray: AP and lateral of humerus and elbow

* CT scan: helpful when suspecting shear fracture of capitulum or trochlea

Question 16

Distal humeral fracture classification

Answer 16

• supracondylar, distal single column, distal bicolumnar, and coronal shear fractures

Question 17

Distal humeral fracture treatment

Answer 17

• goal is to restore ROM 30-130° flexion (unsatisfactory outcomes in 25%)

• non-operative
■ cast immobilization (in supination for lateral condyle fracture; pronation for medial condyle fractures)

• operative
■ indications: displaced, supracondylar, bicolumnar
■ closed reduction and percunatneous pinning; ORIF; total elbow arthroplasty (bicolumnar in elderly)